Comprehensive genomic profiling of high-grade serous ovarian carcinoma from Chinese patients identifies co-occurring mutations in the Ras/Raf pathway with TP53.

High-grade serous ovarian carcinoma (HGSOC) is a major form of ovarian epithelial tumor that is often diagnosed only at an advanced stage when it is already highly aggressive. We performed comprehensive genomic profiling using an analytically validated clinical next-generation sequencing assay to identify genomic alterations in 450 cancer-related genes in a cohort of 88 Chinese HGSOC patients. Overall, we detected 547 genomic alterations with an average of 6.2 alterations per tumor. Most of these HGSOC tumors had low tumor mutation burden and were microsatellite stable. Consistent with earlier studies, TP53 mutations were present in the majority (96.6%) of the tumors studied, and mutations in BRCA1/2 that affect DNA repair were also detected frequently in 20.5% of the tumors. However, we observed a 10.2% of mutated genes in the Ras/Raf pathway, all co-occurring with TP53 mutations in the same tumor, which was unrecognized previously. Our results show that in HGSOC patients, there may be an unrecognized co-occurrence of TP53 mutations with mutations in Ras/Raf pathway.